‘It happened once in Paris that a certain sorceress impeded a man who had left her so that he could not have intercourse with another woman whom he had married. So she made an incantation over a closed lock and threw the lock into a well, and the key into another well, and the man was made impotent. But afterwards, when the sorceress was forced to acknowledge the truth, the lock was retrieved from the one well and the key from the other, and as soon as the lock was opened, the man became able to have intercourse with his wife.’

This story comes from Thomas of Chobham’s Summa confessorum, probably completed before 1217, and opens Catherine Rider’s book. The magic worked by the sorceress using locks and keys has parallels in other medieval stories that employ the same motif, as well as an obvious symbolism. In the early-modern period, one cure for magically-caused impotence was for the man to urinate through the keyhole of the church where he was married. The idea that the magic was performed by the man’s former lover also seems to reflect a widespread belief that surfaces in the trials of sorceresses in the fourteenth century (p. 98). Rider argues that though Thomas may not have been recording an actual event, he was probably referring to real beliefs and practices. While acknowledging the difficulties involved in finding evidence for the practice of impotence magic as seen through the prism of learned writings, she asserts that we can still learn much about this branch of ‘popular magic’.

The book is constructed around the contribution of three university-based disciplines to discussion on the dangers of impotence magic and its cures—canon law, theology, and medicine. These disciplines shared terminology, and, in particular, the use of the term maleficium to denote impotence that was caused by non-physical means like putting substances under the couple’s bed, in their house, or by a road where they would walk, not to mention Thomas’s case of locking a lock and throwing it down a well. They acknowledged the existence of physical causes of impotence, and the importance of distinguishing physical from non-physical causes. In other respects discussion of magically-caused impotence in these disciplines evolved more or less independently, and reflected the particular institutional imperatives of each. Nevertheless in her ‘Introduction’ Rider signposts two wider developments in intellectual and religious history that helped academic discussion of impotence magic to reach new levels of sophistication. The first was the translation of magical texts from Arabic into Latin, the second was the pastoral movement of the thirteenth century that gave rise to Thomas of Chobham’s Summa confessorum, and affected both canon law and theology.

Before the scholastics began to grapple with new texts and new religious imperatives there was already a flourishing practice of impotence magic. Rider picks up its traces in the literature and curse tablets of the ancient world. Unfortunately for our knowledge of magical practice later, there was no medieval equivalent to the curse tablets recording actual spells that were cast. One ancient learned discipline was already concerned with impotence magic, for Latin medical writers were already prescribing remedies for both natural impotence and maleficium, even if they did not use that specific term for magical practices. Christian writers associated magic very strongly with demons and idolatry, following Augustine. The first surviving medieval discussions of impotence magic occur in the writings of Hincmar, archbishop of Rheims from 845 to 882. Hincmar was very interested in marriage law and advised bishops and rulers in several high-profile cases, including two in 860 that led him to say that magic could cause impotence. The first case concerned the attempts of King Lothar II of Lotharingia to divorce his wife, Theutberga, and marry his concubine, Waldrada. Hincmar suggested that Waldrada has bewitched Lothar and caused him to hate his wife. As well as quoting earlier Christian writers who had discussed magic, Hincmar seems to have drawn on actual cases of love magic that had occurred in his archdiocese. In this particular case he does not distinguish impotence magic from other forms of love or hate magic. He also describes a range of magical practices in detail, using the bones of the dead, ashes, pubic hair, parts of serpents, and much else.

In the second case Hincmar singled out impotence magic for special attention. It concerned an Aquitanian count called Stephen, who was betrothed to the daughter of another count, Raymond. In justifying an annulment on grounds of impotence, Hincmar discussed magically-caused impotence as a subset of such cases. Hincmar’s discussion in a short paragraph beginning with the words Si per sortiarias (‘if by sorceresses…’) was to become the source of all subsequent canon law on magically-caused impotence. What he actually meant to say on the subject of the remarriage of partners affected by such impotence has been disputed by modern historians of marriage law, though it is clear that medieval canonists assumed such remarriage was permissible in these cases. Similarly foundational for later discussions by medical writers was the chapter on maleficium in the Pantegni of Constantine the African (d. before 1099), absent in Constantine’s Arabic source, Haly Abbas. In it he mentions cures using animal parts in forms of counter-magic as well as an ‘ecclesiastical cure’ through a cleansing communion ritual, with an amuletic parchment to take home.

These earlier materials were assimilated and commented on in the twelfth century by Gratian in his Decretum, and the ‘decretists’ who followed him, by Peter Lombard in the Sentences, and the extraordinarily influential (but now little known) medical Practica of Roger de Barone. By these conduits magical impotence entered the mainstream of scholasticism in canon law, theology, and medicine. At the same time the translation of magical texts in the twelfth and thirteenth centuries vastly increased the amount of information that writers about magically-caused impotence could draw on in theory—whether in fact they did do so is much more doubtful, with the exception of Albertus Magnus. Certainly the newly-available texts had little or no impact on magical practice, where the exotic names and characters found in the magical texts are not reflected in the recorded case histories that resemble much more closely Thomas of Chobham’s story of the lock thrown down the well.

The four chapters in which Rider examines the literature of confessors’ manuals, canon law, theology, and medicine in the thirteenth and fourteenth centuries are the climax of the book. They are necessarily based on a sampling of this literature, for by this time the volume of commentary and discussion cannot be summarized by the author exhaustively. Nevertheless there is not space enough in this review to do justice to the extraordinary richness and variety of the material that is brought to light just by concentrating on the one topic of impotence magic. Each of the three major disciplines threw up authors who emphasized distinctive aspects of the topic—in canon law it was the doubtful legality of the incantations and medicines offered by practitioners attempting to counter impotence magic; in theology it was the presence and agency of demons in the practice of impotence magic; in medicine it was the attempt to offer physical explanations for methods of causing impotence which other writers called maleficium. Rider argues that despite the originality of authors in all three disciplines in the thirteenth century, and to a lesser degree in the fourteenth, we should assume that popular magic went on pretty well unchanged. There is nothing to suggest that practices of impotence magic changed significantly over the medieval period as a whole.

‘By 1400, magically-caused impotence was a clearly defined phenomenon and the rules that governed cases were well established’ (p. 186). Writers had by this time, it seemed, little new to say, and were saying less. Nevertheless, Rider argues that appearances are deceptive. She argues that in the early-fifteenth century there emerged a new stereotype of a magic-worker, the witch. Amongst all the other things they did (fly to sabbaths, orgies, murder babies) they planned how to do magical harm to their neighbours, one form of which was causing impotence. Concern about this was most clearly reflected, Rider claims, in medical compendia. She cites the descriptions of cases of impotence caused by witchcraft in writings by Niccolo Falcucci, Antonio Guarnieri, and Jacques Despars. At the same time the relative independence of the discourses of canon law, theology, and medicine was collapsing in the face of a shared concerns about the role of the demonic in impotence and other forms of magic. And for the first time, Rider suggests, these changing attitudes to impotence magic may simply reflect anxieties limited to the learned rather than expressions of a change in popular beliefs.

In this short last chapter the reader of her book may begin to feel that the argument is not as securely anchored in close reading of representative texts as earlier chapters. It may be that the author is working outside her comfort zone, and certainly her choice of medical writers to discuss here is arguably biased towards an unrepresentative minority rather than the majority. Admittedly not as much work has been done on fifteenth-century writers on practica and medical encyclopedias as would enable us to come to a conclusive judgement, but such works as the Breviarium Bartholomei of John of Mirfield and its successors in England, which do deal with maleficium, do not suggest new concerns with witchcraft. They continue to recommend magical counter-cures that would mostly have been familiar to Gilbertus Anglicus and other thirteenth-century authorities. Perhaps those concerned with witchcraft were localized and exceptional rather than representative of the majority.

There is still a considerable terrain to be explored, we might conclude. Surviving from the fourteenth and fifteenth centuries, there is a body of Latin and vernacular literature in remedy and commonplace books which might illustrate popular beliefs and practice in respect of impotence magic. One suspects there may be many more cases of magical practice to be disinterred from the records of bishops’ visitations and church courts. It is an exciting thought that we might be able to see as a result of this kind of investigation if the practice of impotence magic in these last centuries showed any evidence of the influence of learned writings on magic. But this thought should not be held against the author of this book, who has delivered an exceptional clearly argued study of learned discussions of impotence magic. The book ends with a very useful edition of the Latin text (with translation) known as ‘Remedies against magic’, compiled around 1300 by an author or authors who clearly used Constantine’s Pantegni on magically-caused impotence as a starting point.

If this study suggests that the practice of impotence magic by real people in the middle ages changed little over the centuries, by contrast with the increase in sophistication and variety of learned discourse, that is only what we might have expected. Some of the practices described in this book have clear counterparts in love magic even today. They do not appear, however, to generate the same level of learned interest.